Short-circuit Current Density Isc Research Articles

Design and Device Modeling of Lead Free CsSnI3 Perovskite Solar Cell

Research of lead-free Perovskite based solar cells has gained speedy and growing attention with urgent intent to eliminate toxic lead in Perovskite materials. The main purpose of this work is to supplement the research progress with comparative analysis of different lead-free Perovskite based solar cells by numerical simulation method using solar cell capacitance simulator (SCAPS-1D) software. The environmental friendliness and excellent thermal stability proves Cesium Tin Iodide (CsSnI3) as one of the promising materials for the commercialization of the Perovskite solar cells. However, CsSnI3 solar cells suffer from poor efficiency due to having low open-circuit voltage, VOC attributed to poor absorber film quality as well as energy level mismatch at the interfaces between different layers like transparent front contact. The architecture of the solar cell is n-i-p device structure acts as light CsSnI3 absorber active layer, TiO2 as electron transport layer and Spiro-OMeTAD as hole transport layer with device structure FTO/ TiO2/CsSnI3 / Spiro-OMeTAD /Au. The open circuit voltage Voc, short circuit current density Isc, fill factor and power conversion efficiency Voc=1.09V, Jsc=28.85mA/cm2, FF=88.65%, eta=28.09%, V_MPP=0.99V, J_MPP=28.15 mA/cm2 respectively.

Investigation on Design and Device Modeling of High Performance CH3NH3PbI3-xClx Perovskite Solar Cells

Perovskite solar cells fabricated with inexpensive and simple technology exhibits high efficiency has witnessed worldwide boom in research. The optimization of solar cell can be done through modeling and simulation. The optical and electrical modeling are the ways to optimize different parameter such as thickness, defect density, doping density and material selection for fabricating stable and highly efficient perovskite solar cells. In this research work, electrical modeling of solar cell is done throughSolar Cell Capacitance Simulator(SCAPS-1D).The architecture of the solar cell is n-i-p device structure. CH3NH3PbI3-xClx acts as light absorber active layer, TiO2 as electron transport layer and Spiro-OMeTADas hole transport layer with device structure FTO/ TiO2/ CH3NH3PbI3-xClx/ Spiro-OMeTAD/Au. The open circuit voltage Voc, short circuit current density Isc, fill factor and power conversion efficiency are 1.28 V, 21.63 mA/cm2, 0.78 and 21.53% respectively. The result showed that the optimize parameter can be applied for fabrication of the solar cell experimentally. Various metal contact materials of the anodeare also studied and analyzed.

Effect of Silicon Surface Treatment on the Electrical and Photoelectric Properties of Nanostructured MoOx/n-Si Heterojunctions

The paper presents the results of studies of the effect of silicon surface treatment on the electrical and photoelectric properties of nanostructured MoOx/n-Si heterojunctions. The nanostructured heterojunctions MoOx/n-Si, were prepared by deposition of thin films of molybdenum oxide (n-type conductivity) by reactive magnetron sputtering in the universal vacuum system Leybold Heraeus L560 on the nanostructured silicon substrates (n-type conductivity), which were made by chemical etching with the assistance of silver nanoparticles. Dark and light volt-ampere (I – V) characteristics of the heterojunctions under study were measured, the value of the potential barrier height, the values of the serial Rs and the shunt Rsh resistance at room temperature were determined. It was established that the silicon surface treatment does not affect the potential barrier height, but significantly affects the values of serial Rs and shunt Rsh resistance. The electrical and photoelectric properties of the obtained structures were investigated, the dominant mechanisms of current transfer through the heterostructures under forward bias are well described in the framework of emission-recombination and tunneling models with the presence of interface states. The main mechanism for the charge carrier transport through heterojunctions with the reverse bias is the Frenkel–Pool emission. Investigation of photoelectric properties of heterojunctions MoOx/n-Si was carried out at illumination by white light with intensity Popt = 80 mW/сm2. It was established that the heterostructure No.5 MoOx/n-Si with grown nanowires and etched silver nanoparticles has a maximum open-circuit voltage Voc = 0.17 V, short-circuit current density Isc = 10 mA/cm2. The possibilities of using the obtained heterostructures as photodiodes were analyzed.

Graphite/p-SiC Schottky Diodes Prepared by Transferring Drawn Graphite Films onto SiC

Graphite/p-SiC Schottky diodes are fabricated using the recently suggested technique of transferring drawn graphite films onto p-SiC single-crystal substrates. The current–voltage and capacitance–voltage characteristics are measured at different temperatures and at different frequencies of a small-signal AC signal, respectively. The temperature dependences of the potential-barrier height and of the series resistance of the graphite/p-SiC junctions are measured and analyzed. The dominant mechanisms of the charge–carrier transport through the diodes are determined. It is shown that the dominant mechanisms of the transport of charge carriers through the graphite/p-Si Schottky diodes at a forward bias are multi-step tunneling recombination and tunneling described by the Newman formula (at high bias voltages). At reverse biases, the dominant mechanisms of charge transport are the Frenkel–Poole emission and tunneling. It is shown that the graphite/p-SiC Schottky diodes can be used as detectors of ultraviolet radiation since they have the open-circuit voltage Voc = 1.84 V and the short-circuit current density Isc = 2.9 mA/cm2 under illumination from a DRL 250-3 mercury–quartz lamp located 3 cm from the sample.